There is some confusion about why you see sometimes see whole numbers and why sometimes these are set to one or two (in the case of salt) decimal places. Although including a Front of Pack format on your label is optional, if you do decide to include it, it must follow the rules. These are different for products containing more than 10g of the nutrient and less than 10g etc.
You can read more in section 4 of the paper here:
https://www.gov.uk/government/publications/front-of-pack-nutrition-labelling-guidance
Alternatively, please contact us for any related queries.